Freeze-drying comes to fore in nutraceuticals

15 Jun 2020 --- Freeze-drying technology is seeing a resurgence in nutraceuticals thanks to its ability to maintain the viability of cells in the food product, which is as important as ensuring a long shelf-life. This is according to Diana Morris, Country Manager UK at European Freeze Dry, who tells NutritionInsight about the potential for the technology to grow further. She also details the challenges of working with various original ingredients, which requires a range of freeze-drying methods.

“An extremely gentle drying process is needed to ensure a good-quality final product that continues to offer health benefits. This is while creating a supplement that won’t deteriorate over a long period of time. Freeze-drying removes the water content from products over the course of up to 72 hours, leaving the final product structurally stable and maintaining all the nutritional and health benefits of the original product,” she explains.

Morris continues that compared to more aggressive drying methods such as spray drying or air drying, freeze-drying methods are proven to retain the purity of the product. This is even when they are ground down into a powder. Therefore, delicate ingredients can still be dried for a longer shelf-life without impacting the quality of the product. Additionally, freeze-drying means that there is a much-reduced potential for microorganisms existing in such low amounts of water, ensuring that nutraceuticals can stay safe to consume for up to two years.

At Europe Freeze Dry, all products for freeze-drying start as frozen raw materials before undergoing a process known as sublimation. A deep vacuum is applied, creating a condition where ice or water cannot exist. The pressure from the vacuum, with a controlled amount of heat applied, causes the ice to leave the product as a vapor trail. This is then captured on an ice condenser within the freeze drier, upon which the vapor forms again as ice.

After 24 to 72 hours, the product can be supplied as a stable supplement or ground down into a powder, which can be inserted into tablets. The process means that the product also retains its natural color, shape and nutritional characteristics. For nutraceutical producers, raw materials such as rosehip, elderberry or animal liver can be packaged in a tablet. This can be supplied to chemists or sold online, meeting the consumer demands for new superfood supplements.

“Additionally, many customers have run trials on the bioavailability of their products with favorable results. The freeze-drying process can create larger or more intensive doses. However, numbers of bioavailability are determined and evaluated by the customer rather than ourselves, the processor,” details Morris.

The company uses trial drying in its laboratory dryers in both the UK and Denmark to fully understand the properties of a product.Room for expansion
Understanding the nature of a compound or product and how it will react in the freeze-dryer process is always the initial challenge, explains Morris. “Each original ingredient is different, and as a result, we have to work with the nutraceutical company to test and scale the best methods to freeze-dry without losing the key nutrients. Some ingredients can handle a quicker freeze-drying process at a higher temperature without being altered. Meanwhile, others require a more gentle approach.”

The company uses trial drying in its laboratory dryers in both the UK and Denmark to fully understand the properties of a product before scaling up to mainstream manufacture. “This also gives our customers confidence that the process works and retains the quality of the original product when we are commission-drying their product,” says Morris. 

She continues that the company has been freeze-drying products destined for nutraceutical applications for many years, be it enzymes, fruits or seaweed. “However, we are now seeing more growth in applications relating to men’s health, general well-being and enzymes for a healthy gut,” concludes Morris. 

In May, European Freeze Dry noted that freeze-dried foods are in the spotlight with the ongoing COVID-19 pandemic, with many people staying at home and being more resourceful with cooking and ingredients. Last week, the company then unveiled a range of gourmet ingredients designed for snacks and ready meals with a shelf life of up to two years.

By Katherine Durrell